Dielectric relaxation and pyroelectric behaviour of betaine potassium iodide dihydrate

Betaine potassium iodide dihydrate (BKI) is a new compound of the aminoacid betaine with a triclinic symmetry and with the space group P (1) over bar at room temperature. It undergoes a phase transition at 100 K. In this pape r we report a detailed study of the dielectric relaxation and of the pyroel ectric properties of this compound in the temperature range 20-300K. A micr oscopic interpretation of dielectric properties is presented by doing a com parison between the dielectric dispersion behaviour and the results obtaine d in the study of Raman scattering of BKI.